A hernia is the protrusion of part of a body part or structure through a defect in the wall of a surrounding structure. Most commonly, a hernia is the protrusion of part of abdominal contents, including bowel, through a tear or weakness in the abdominal wall, or through the inguinal canal into the scrotum.
An abdominal hernia is repaired by suturing or stapling a mesh patch over the site of the tear or weakness. The mesh patch has a rough surface that can irritate the bowel and cause adhesions. It is therefore preferred to install the patch properitoneally (the terms properitoneal and preperitoneal are used as synonyms). The mesh patch is preferably attached to the properitoneal fascia of the abdominal wall and covered by the peritoneum. To attach the mesh patch to the properitoneal fascia, the peritoneum must be dissected from the properitoneal fascia. This is a difficult process which involves the risk of puncturing the peritoneum. Moreover, strands of properitoneal fat interconnecting the peritoneum and the properitoneal fascia make it difficult to see the site of the hernia.
The abdominal wall includes various layers of tissue. The peritoneum (P) is the innermost layer. Overlying the peritoneum are several layers of tissue, including the properitoneal fat layer (FL) and the properitoneal fascia (F). The properitoneal fascia is the layer to which a mesh patch is preferably attached in hernia repair. The properitoneal fat layer separates the peritoneum from the properitoneal fascia. The properitoneal fat layer is relatively weak, which enables the peritoneum to be separated relatively easily from the fascia
When the peritoneum is separated from the fascia, separation takes place at or in the properitoneal fat layer. The properitoneal fat layer can remain attached to the properitoneal fascia, or can come away with the peritoneum. Alternatively, part of the properitoneal fat layer can remain attached to the peritoneum and part of the fat layer can come away attached to the peritoneum. Because of the uncertainty in the point of separation, the layer which is detached will be called the peritoneum, and the layer from which the peritoneum is detached will sometimes be denoted as the overlying layer. Additional layers of tissue lie between the properitoneal fascia and the skin.
An inguinal hernia occurs when the contents of the abdominal cavity break through the abdominal wall. As described above, a hernia is repaired by attaching a piece of mesh to the abdominal wall. To prevent the mesh from causing trauma to the bowel, either through irritation of the bowel by the rough surface of the mesh, or by adhesion of the bowel to the mesh, it is preferred to attach the mesh to the properitoneal fascia With the mesh attached to the fascia, the peritoneum covers the mesh and isolates the bowel from the mesh.
Conventional techniques of attaching the mesh patch to the properitoneal fascia, both laparoscopic and normal, involve blunt dissecting the peritoneum away from the properitoneal fascia, working from inside or outside the belly. The apparatus and methods according to the invention enable the peritoneum to be separated from the properitoneal fascia and the mesh patch attached to the fascia without entering the belly.
Although the following description will describe apparatus and methods according to the invention with respect to hernia repair, the inventive apparatus and methods are not restricted to hernia repair. The apparatus and methods can also be used in other procedures in which one layer of tissue is separated from another to form a working space between the layers. These procedures include thoracoscopy in patients with pleural adhesions; pericardioscopy, or the introduction of an endoscope into the pericardial cavity, in patients with pericardial adhesions; retroperitoneal lymph node dissection, in which the peritoneum on the distal aspect of the abdominal cavity is separated from the underlying tissue which includes lymph nodes; and in separating a blood vessel from surrounding connective tissue in the course of, for example, a femoropopliteal arterial bypass graft procedure.
Laparoscopic techniques to perform hernia repair are being used increasingly frequently. In the conventional procedure for carrying out a hernia repair laparoscopically, an endoscope and instruments are introduced into the belly through one or more incisions in the abdominal wall, and advanced through the belly to the site of the hernia Then, working from inside the belly, a long incision is made in the peritoneum covering the site of the hernia. Part of the peritoneum is dissected from the properitoneal fat layer to provide access to the fat layer. This is conventionally done by blunt dissection, such as by sweeping a rigid probe under the peritoneum. In this procedure, it is difficult to dissect the peritoneum cleanly since patchy layers of properitoneal fat tend to adhere to the peritoneum.
In an alternative known laparoscopic hernia repair procedure, the belly is insufflated. An incision is Made in the abdominal wall close to the site of the hernia The incision is made through the abdominal wall as far as the properitoneal fat layer. The peritoneum is then blunt dissected from the properitoneal fat layer by passing a finger or a rigid probe through the incision and sweeping the finger or rigid probe under the peritoneum. After the peritoneum is dissected from the properitoneal fat layer, the space between the peritoneum and the properitoneal fat layer is insufflated to provide a working space in which to apply the mesh patch to the properitoneal fascia.
During the blunt dissection process, it is easy to puncture through the peritoneum, which is quite thin. Additionally, after initial dissection of the properitoneal space, known surgical procedures require introduction of various instruments in the space to conduct the surgery. These instruments can cause inadvertent puncture of the peritoneum wall after the initial dissection. A puncture destroys the ability of the space between the peritoneum and the fascia to hold gas insufflation; pressurized gas can travel through a puncture in the peritoneum to allow the fluid to migrate to the abdominal cavity and degrade the pressure differential maintaining the properitoneal cavity. Also, it is difficult to dissect the peritoneum cleanly since patchy layers of properitoneal fat tend to adhere to the peritoneum. Clearing difficult adhesions can sometimes result in a breach of the peritoneum itself.
U.S. Pat. No. 5,309,896 (of which this application is a C.I.P.), discloses a laparoscopic hernia repair technique that enables a mesh patch to be attached to the properitoneal fascia without breaching the peritoneum. An incision is made through the abdominal wall as far as the properitoneal fat layer. A multi-chambered inflatable retraction device is pushed through the incision into contact with the peritoneum, and is used to separate the peritoneum from the overlying tissue layer. The main end chamber of the inflatable retraction device is then inflated to elongate the inflatable retraction device towards the site of the hernia As it inflates, the inflatable retraction device gently separates more of the peritoneum from the overlying tissue layer. Once the main chamber of the inflatable retraction device is fully inflated, a second inflatable chamber is inflated. The second inflatable chamber enables the inflatable retraction device to continue to separate the peritoneum from the other tissue layers after the main inflatable chamber has been deflated.
One or more apertures are then cut in the envelope of the main inflatable chamber to provide access to the site of the hernia for instruments passed into the nain chamber. With such an arrangement, instruments pass through the main chamber while the main chamber remains between the peritoneum and the overlying layers. In this way, a patch can be attached to the properitoneal fascia without breaching the peritoneum.
Another device for separating tissue layers is disclosed in U.S. patent application Ser. No. 07/911,714, of which this application is a C.I.P. The device includes a main envelope that defines a main inflatable chamber. The apparatus also includes an introducing device for introducing the main envelope in a collapsed state between the first layer of tissue and the second layer of tissue. The introducing device inflates the main envelope into an expanded state to separate the first layer of tissue from the second layer of tissue, and to create a working space between the first layer of tissue and the second layer of tissue. Finally, the apparatus includes an insufflating device for introducing insufflation gas into the working space between the first layer of tissue and the second layer of tissue.
In a method according to U.S. application Ser. No. 07/911,714, a first layer of tissue is separated from a second layer of tissue using a main envelope (defining a main inflatable chamber) and insufflation gas. The main envelope is introduced in a collapsed state between the first and second layers of tissue, and the main envelope is then inflated into an expanded state to create a working space between the first and second layers of tissue. Finally, insufflation gas is introduced into the working space between the first and second layers of tissue.
U.S. Ser. No. 07/911,714 discloses a two-component apparatus including an inflatable main envelope and a device for introducing the main envelope (together constituting a first component which separates a first layer of tissue from a second layer of tissue to create a working space) and an insufflation device which insufflates the working space to maintain separation of the first layer of tissue from the second layer. The insufflation device is tubular, has an anchor flange slidably mounted on it, and has a toroidal inflatable chamber at its distal end. The anchor flange and toroidal inflatable chamber together form a gas-tight seal with the second layer of tissue.
In a method disclosed in U.S. Ser. No. 07/911,714 for using the two-component apparatus, the introducing device pushes the main envelope in a collapsed state through an incision through the second layer of tissue to place the main envelope between the first and second layers of tissue. The main envelope is then inflated to gently separate the first and second tissue layers. An endoscope may be passed through the bore of the introducing device into sthe main chamber to observe the extent of separation of the layers of tissue. The main envelope is then returned to a collapsed state, and the main envelope and introducing device are removed through the incision. Next, the insufflating device is inserted into the incision so that its distal end projects into the working space between the two layers of tissue, and the toroidal inflatable chamber is inflated. The anchor flange is slid distally along the insufflating device to compress the second layer of tissue between it and the expanded toroidal inflatable chamber, and thus to form a gas-tight seal. Insufflating gas is then passed through the insufflating device into the working space to maintain the separation of the first layer of tissue from the second. An endoscope may be passed through the bore of the insufflating device into the working space to observe within the working space.
A two-component apparatus (of the type disclosed in referenced U.S. Ser. No. 07/911,714) for separating tissue layers and insufflating the space between the separated layers is shown in FIGS. 1A-1C and 2A-2B. FIG. 1A shows a partially cut-away view of separation component 1 of the apparatus. In separation component 1, introducer tube 3 is a rigid tube having a bore with a circular cross section that can accommodate an endoscope.
The proximal end of introducer tube 3 is fitted with a port 5, in the proximal end 7 of which is mounted a flapper valve 2. Shutter 6 of flapper valve is operated by button 9. Seat 4 of the flapper valve additionally forms a gas-tight seal with an endoscope or other instrument inserted though the flapper valve into the bore of introducer tube 3. Port 5 is also fitted with a valve 11 to which a supply of a suitable inflation fluid can be connected.
Main envelope 12 defmes a main inflatable chamber 13. Main envelope 12 is fitted to distal end 15 of introducer tube 3. Main envelope 12 is shown in a collapsed state in FIGS. 1B and 1C. Dotted line 12X indicates the extent of main envelope 12 with chamber 13 in its expanded state. It should be noted that although the main envelope 12 is illustrated as generally spherical, it can be formed as oblong, "hockey puck" or disc shaped, kidney bean shaped or in other shapes as suited for the particular dissection contemplated.
Main envelope 12 is preferably formed from an elastomeric material, such as latex, silicone rubber, or polyurethane. The main envelope can also be formed from a thin, inelastic material such as Mylar.RTM., polyethylene, nylon, etc. If an inelastic material is used, it should be suitably packaged to fit inside the bore of introducer tube 3 when in its collapsed state.
The preferred elastomeric main envelope 12 can be simply attached to the distal end 15 of the introducer tube 3 by stretching the main envelope over the distal end of the introducer tube, as shown in FIG. 1B. The main envelope is then kept in place by friction resulting from the tension caused by stretching. A suitable adhesive, such as an epoxy or cyanoacrylate adhesive, may additionally or alternatively be used. Other means of attaching the main envelope to the inside or the outside of the introducer tube can be used.
After attachment, main envelope 12 is inverted into the bore of the introducer tube, as shown in FIG. 1C. Inverting the main envelope into the bore of the introducer tube makes it easier to use the introducer tube to pass the main envelope through an incision and place it adjacent to the peritoneum, as will be described.
The first part of a method (described in U.S. Ser. No. 07/911,714) using separation component 1 of the two-component apparatus of FIGS. 1A-1C and 2A-2B to separate a first layer of tissue from a second layer of tissue will next be described with reference to FIGS. 3A-3E (the entire method, for repairing a hernia, will be described with reference to FIGS. 3A-3I).
FIGS. 3A-3I show a longitudinal cross section of the lower abdomen. As indicated by FIG. 3A, an incision about 12-15 mm. long is made in the abdominal wall (AW), and is carried through the abdominal wall as far as, and including, the properitoneal fat layer (FL). Distal end 15 of introducer tube 3 of separation component 1 is then inserted into the incision to bring the distal end into contact with the peritoneum (P). Additional gentle pressure detaches the part of the peritoneum in the immediate vicinity of the incision from the overlying layer, as shown in FIG. 3B. FIG. 3B shows the peritoneum (P) detached from the properitoneal fat layer (FL). The deflated main envelope cannot be seen in FIG. 3B because it is inverted within the bore of introducer tube 3.
A source of a suitable inflation fluid (not shown) is connected to valve 11. A gas, preferably air, is the preferred inflation fluid, but other gases, such as carbon dioxide, can be used. A liquid, such as saline solution, can be used, but liquids are less preferable than gases because liquids change the optical properties of any endoscope inserted into main inflatable chamber 13. The flow of inflation fluid is turned on, which ejects the main envelope 12 of main inflatable chamber 13 from the bore of introducer tube 3.
The inflation fluid progressively expands the main envelope 12, and hence the main inflatable chamber 13 defmed by the main envelope, into an expanded state (as shown in FIG. 3C). The main envelope expands between the peritoneum and the properitoneal fascia, and gently and progressively detaches an increasing area of the peritoneum from the overlying layer as it expands. When the main envelope is in its expanded state, the main inflatable chamber is preferably about 4"-6" (100-150 mm) in diameter.
Early in the process of expanding the main envelope 12, an endoscope E is inserted into flapper valve 2 in port 5, as shown in FIG. 3C. Endoscope E is passed through the bore of introducer tube 3 into the main inflatable chamber 13. Once partially expanded, main envelope 12 is sufficiently transparent for the extent of the detachment of the peritoneum to be observed through the endoscope.
When a sufficient area of the peritoneum has been detached, the supply of inflation fluid is turned off. The inflation fluid is then vented from the main inflatable chamber, and main envelope 12 returns to its collapsed state. The peritoneum remains detached from the properitoneal fascia, however, as shown in FIG. 3D. Separation component 1, including the collapsed main envelope, is then withdrawn from the incision I (FIG. 3E).
Insufflation component 21 (shown in FIGS. 2A and 2B) of the two-component apparatus of FIGS. 1A-1C and 2A-2B will next be described. Insufflation component 21 comprises inner tube 35 and outer tube 37 mounted coaxially, with the outer tube covering the inner tube over most of the length of the inner tube. The inner tube is similar to the introducer tube 3 (FIG. 1A), and is a rigid tube having a bore with a circular cross section that can accommodate a 10 mm endoscope.
The proximal end of inner tube 35 is fitted with a port 25, the proximal end 27 of which has a flapper valve 32. Shutter 36 of the flapper valve is operated by button 29. Seat 34 of the flapper valve forms a gas-tight seal with an endoscope (not shown) or an obturator (such as obturator 33) inserted though the flapper valve into the bore of inner tube 35. Port 25 is also fitted with a first valve 31 to which a supply of a suitable insufflation fluid can be connected.
Distal end 41 of outer tube 37 stops short of distal end 39 of inner tube 35. Insufflation component 21 includes a toroidal inflatable chamber 43. Envelope 45 of toroidal chamber 43 is a cylindrical piece of a thin elastomeric material, such as latex, silicone rubber, or polyurethane. Envelope 45 is placed over the distal ends of the inner tube and the outer tube. Proximal end 47 of envelope 45 is attached to distal end 41 of the outer tube, and distal end 49 of envelope 45 is attached to distal end 39 of the inner tube 35.
The bore of outer tube 37 is spaced from the outer surface of inner tube 35. Annular space 51 between the inner tube and the outer tube interconnects toroidal chamber 43 and a second valve 53. Second valve 53 is connected to a source of a suitable inflation fluid (not shown). Thus, toroidal envelope 45 can be inflated using an inflation fluid passing into toroidal inflatable chamber 43 (the volume enclosed by envelope 45) via the second valve 53 and the annular space 51. Toroidal inflatable envelope 45 is shown in its collapsed state in FIG. 2A, and in its expanded state in FIG. 2B.
Anchor flange 55 is slidably mounted on the outer tube 37, and can be locked in a desired position along the length of the outer tube with a simple over-center action locking lever (not shown). As will be described in detail below, the anchor flange and the toroidal inflatable chamber, in its expanded condition, enable the insufflator component 21 to form a gas-tight seal to prevent insufflation gas passed through the insufflator component from escaping.
The use of insufflation component 21 in the second part of the method of FIGS. 3A-3I using the two-component apparatus of FIGS. 1A-1C and 2A-2B will next be described. It is preferred to use separation component 1 in conjunction with the first part of the method (described with referenced to FIGS. 3A-3E) and for dissecting the first and second tissue layers, but the second part of the method (using insufflation component 21) may be used in following any other dissection operation including manual dissection with an endoscope, graspers, operating scope or any blunt instrument which may be used to dissect the tissue layers by sweeping the area between the layers.
With reference to FIG. 3F, obturator 33 of component 21, having blunt tip 57, is inserted past flapper valve 32 (shown in FIG. 2B) into the bore of inner tube 35. Tip 57 of obturator 33 projects beyond the distal end of the inner tube to provide insufflation component 21 with a blunt nose. The blunt nose enables the distal end of insufflation component 21 to be atraumatically inserted into the properitoneal space through incision I. The insufflation component is advanced through the incision until the proximal end of the cylindrical envelope 45 is in the properitoneal space, clear of the incision, as shown in FIG. 3F.
A suitable source (not shown) of an inflation fluid is attached to second valve 53. A gas, such as air or carbon dioxide, can be used for the inflation fluid; alternatively, a liquid, such as saline can be used. Since the volume of inflation fluid required to inflate the toroidal inflatable chamber is small, about 15 ml in the preferred embodiment, the inflation fluid can be forced into the toroidal inflatable chamber from a large syringe. Inflation fluid is fed into toroidal inflatable chamber 43 to expand the toroidal inflatable chamber to its expanded condition, as shown in FIG. 3G.
Anchor flange 55 is then advanced in the direction of arrow 59 along outer tube 37 to bring anchor flange 55 into contact with the skin of the abdominal wall (as shown in FIGS. 3G and 3H). Insufflation component 21 is then gripped, and the anchor flange is further advanced slightly. This forces the expanded toroidal inflatable chamber 43 into contact with the overlying layer, and slightly compresses the abdominal wall (including the overlying layer but excluding the peritoneum) between the toroidal inflatable chamber and the anchor flange. Once adjusted, the anchor flange is locked in position on the outer tube. The expanded toroidal inflatable chamber is held against the overlying layer, and forms a gas-tight seal between the insufflation component and the abdominal wall (including the overlying layer but excluding the peritoneum).
A suitable source (not shown) of an insufflation gas is attached to first valve 31, and insufflation gas is passed through the bore of inner tube 35 into the working space between the peritoneum and the overlying layer created by separating by the peritoneum from the overlying layer using the separation component of the apparatus in the first part of the method described above. The pressure of the insufflation gas re-separates the peritoneum from the overlying layer, as shown in FIG. 3H, and provides a working space in which repair of the hernia can be carried out. The obturator is removed from the bore of inner tube 35. The bore of inner tube 35 can then be used to pass instruments, such as the endoscope, into the working space to perform the repair procedure. Insufflation pressure is maintained by flapper valve 32.
As part of the hernia repair procedure, additional gas-tight trocar sheaths are inserted through the abdominal wall into the working space, as shown in FIG. 3I. An endoscope (not shown) can be passed into the working space through the bore of inner tube 35, or through one of the additional trocar sleeves for observation. If the properitoneal fat layer remains attached to the properitoneal fascia, it is scraped off the fascia around the site of the hernia so that the patch can be attached directly to the fascia
A patch, preferably a Dacron.RTM. or Teflon.RTM. mesh, shown gripped by grippers, is passed through the sleeve of one trocar into the working space. Using the grippers, the patch is manipulated to place it in contact with the properitoneal fascia over the site of the hernia The patch is attached to the properitoneal fascia by staples inserted using a stapler passed through the trocar sleeve into the working space. Sutures can alternatively be used to attach the patch to the properitoneal fascia.
After the treatment procedure is completed, first valve 31 is operated to release the insufflation gas from the working space. Second valve 53 is operated to release the inflation fluid from toroidal inflatable chamber 43. Envelope 45 of the toroidal inflatable chamber returns to its collapsed state, flush with the outer surfaces of the inner tube and outer tube 37. Insufflating component 21 is then withdrawn from the incision, and the incision is closed using sutures or clips. The pressure of the viscera against the peritoneum returns the peritoneum into contact with the overlying layer. Over time, the peritoneum reattaches to the overlying layer.
Several embodiments of a one-component apparatus are disclosed in U.S. Ser. No. 07/911,714. Each such one-component apparatus includes assemblies for performing multiple functions, including: introducing and inflating a main envelope to dissect tissue layers within a patient; anchoring the apparatus to the patient and insufflating the working space; and returning the inflated main envelope to a collapsed state. In some of these embodiments, the main envelope is deployed through an elongated tube, and the anchoring means includes an anchor flange slidably mounted on the elongated tube and a toroidal inflatable chamber at the distal end of the elongated tube. The anchor flange and toroidal inflatable chamber can be controlled to form, together, a gas-tight seal with the second layer of tissue.
One-component apparatus 121 (one of the one-component apparatus embodiments disclosed in U.S. Ser. No. 07/911,714) is shown in FIG. 4A. Apparatus 121 is similar to insufflation device 21 of FIGS. 2A-2B, and components of apparatus 121 corresponding to those of device 21 are identified by the same reference numbers as in FIGS. 2A-2B with "100" added thereto. Apparatus 121 comprises tube assembly 160, including an inner tube 135 coaxially mounted inside an outer tube 137. Outer tube 137 covers inner tube 135 over most of the length of the inner tube. The inner tube is a rigid tube having a bore with a circular cross section that can accommodate an endoscope (not shown).
The proximal end of the inner tube 135 is fitted with a port 125, the proximal end 127 of which includes a flapper valve 132. The shutter 136 of the flapper valve is operated by the button 129. Additionally, the seat 134 of the flapper valve forms a gas-tight seal with an endoscope (not shown), or other instrument, inserted though the flapper valve into the bore of the inner tube 135. The port 125 is also fitted with a first valve 131 to which a supply of a suitable insufflation fluid can be connected.
Unlike insufflator device 21 of FIGS. 2A and 2B, the distal end of outer tube 137 extends as far as the distal end of inner tube 135. Tubes 135 and 137 are connected together over a distal portion 167 of their lengths (see detail in FIG. 4B). Circumferential groove 169 is formed in the inner wall of distal portion 167. Groove 169 is shown with a wedge-shaped cross section, but can have other cross sections, such as square, or semi-circular. Circumferential groove 169 retains main envelope 112, which defines main inflatable chamber 113, in the bore of inner tube 135.
Envelope 145 of toroidal inflatable chamber 143 covers the distal part of tube assembly 160. Envelope 145 is a cylindrical piece of thin elastomeric material, such a latex, silicone rubber, or polyurethane. The proximal end 147 and the distal end 149 of the envelope are attached to the outer surface 163 of the tube assembly using a circumferential line of adhesive applied at each end of the envelope. An epoxy or cyanoacrylate adhesive is preferably used. When chamber 143 is in its collapsed state, envelope 145 lies almost flush with the outer surface of tube assembly 160.
Outer tube 137 is spaced from inner tube 135 over at least part of its circumference. Space 151 between the inner tube and the outer tube, and radial passage 161 through the wall of the outer tube interconnect chamber 143 and second valve 153. Second valve 153 is connected to a source of suitable inflation fluid (not shown). Chamber 143 is shown in its collapsed state in FIGS. 4A and 4B, and in its expanded state in FIG. 4C.
Anchor flange 155 is slidably mounted on tube assembly 160, and can be locked in a desired position along the length of the tube assembly with a simple over-center action locking lever (not shown). As will be described below, anchor flange 155 and toroidal inflatable chamber 143 in its expanded condition form a gas-tight seal to prevent insufflation gas from escaping.
The apparatus of FIGS. 4A-4C also includes main envelope 112 detachably attached to the bore of inner tube 135. The main envelope defines main inflatable chamber 113. Main envelope 112 is preferably formed of an elastomeric material such as latex, silicone rubber, or polyurethane (but can also be formed from a thin, inelastic material such as Mylar.RTM., polyethylene, nylon, etc.). If an inelastic material is used for envelope 112, it should be suitably packaged to fit inside the bore of the inner tube when in its collapsed state.
Main envelope 112 is formed such that it has a substantially spherical shape when in its expanded state, and is also formed with a neck 165. Neck 165 has an outside diameter substantially equal to the diameter of the bore of inner tube 135. Neck 165 can be rolled outward a number of times, as in the neck of a common toy balloon, or the neck can be attached to a suitable O-ring 171 as shown in FIG. 4B. The rolled neck, or the O-ring attached to the neck, engages with the circumferential groove 169 in the inner wall in the inner tube to attach main envelope 112 to the inner tube. Main envelope 112 is housed in the bore of the inner tube when the main inflatable chamber is in its collapsed state.
Rip cord 173, attached to neck 165 of main envelope 112, runs proximally up the bore of inner tube 135 and emerges from port 125 through flapper valve 132. The part of the rip cord 173 emerging from the flapper valve can be gripped and pulled in a proximal direction to release the rolled neck 165 or the O-ring 171 from the circumferential groove 169. By pulling further on the rip cord, the entire main envelope can be pulled proximally through the bore of the inner tube.
FIG. 5A shows a one-component apparatus (which is a variation on the apparatus of FIGS. 4A-4C) having an elongated main envelope 112A. As shown in FIG. 5A (and described in referenced U.S. application Ser. No. 07/911,714), tube assembly 160A includes inner tube 135A mounted coaxially inside outer tube 137A, with the proximal and distal ends of the tubes interconnected. Space 151A between the inner tube and the outer tube communicates with the toroidal inflatable chamber through a radial passage in the wall of the outer tube. The space between the inner tube and the outer tube also communicates with the toroidal chamber inflation valve 153A. The bore of the inner tube 135A communicates with the port 125A, fitted with the insufflation valve 185. The port 125A is also fitted with a flapper valve 132A, including the flapper valve seat 134A, which maintains gas pressure when the apparatus is used for insufflation. Flapper valve seat 134A also provides a gas-tight seal around any instrument, such as endoscope E, passed through the flapper valve.
Elongated main envelope 112A is shown in FIG. 5B. The main envelope is an elongated cylinder with a closed distal end 177. The main envelope is preferably formed from an elastomeric material, such as latex, silicon rubber, or polyurethane. Attached to the proximal end of the main envelope is a manifold 175 which mates with the proximal face 127A of the port 125A. The manifold 175 is fitted with an O-ring seal 187, which forms a gas-tight seal with any instrument passed through it. The manifold 175 is also fitted with the main chamber inflation valve 131A to which a supply (not shown) of a suitable inflation fluid can be attached to inflate the main inflatable chamber 112A.
Elongated main envelope 112A is passed through flapper valve 132A into the bore of inner tube 135A. The manifold 175 is engaged with the proximal face 127A of the port 125A. When the manifold is engaged, the distal end 177 of the main envelope projects beyond the distal end of the tube assembly 160A, as shown in FIG. 5C. The distal end of the main envelope is then inverted into the bore of the inner tube 135A, as shown in FIG. 5D.
An endoscope, or other suitable instrument, is inserted through O-ring seal 187 to seal the manifold before inflation fluid is passed through main chamber inflation valve 131A to inflate main inflatable chamber 113A.
Alternatively, seal 187 can be replaced by an additional flapper valve (not shown) so that the main inflatable chamber can be inflated without the need to use an instrument to seal the manifold.
When inflation fluid is passed into main inflatable chamber 113A through valve 131A, distal end 177 of main envelope 112A is ejected from inner tube 135A. The inflation fluid then progressively expands the main envelope 112A, and hence main inflatable chamber 113A defined by the main envelope, into an expanded state as shown in FIG. SA. The part of the main envelope inside the inner tube is subject to the same inflation pressure as the distal end 177 of the main envelope, but is constrained by the inner tube and so does not inflate.
After using main envelope 112A to separate (dissect) the peritoneum from an adjacent tissue layer, as will be described below, the inflation pressure fluid is vented from main inflatable chamber 113A, and main envelope 112A returns to its collapsed state. When the main envelope is in its collapsed state, it can move freely in the bore of inner tube 135. The main envelope is removed from the inner tube by disengaging manifold 175 from the proximal face 127A of port 125A, and using manifold 175 to pull the main envelope proximally through the bore of the inner tube.
Inflation fluid for the toroidal inflatable chamber (envelope 145A of which is shown in FIG. 5A), is passed through toroidal chamber inflation valve 153A. Insufflation gas is passed through insufflation valve 185.
The toroidal inflatable chamber and anchor flange 155A of the embodiment of FIGS. 5A-5D are the same as in the embodiment of FIGS. 4A-4C, and will not be described again.
In a method according to U.S. Ser. No. 07/911,714 of using a one-component apparatus to separate a first layer of tissue from a second layer of tissue, the elongated tube pushes the main envelope in a collapsed state through an incision through the second layer of tissue to place the main envelope between the first layer of tissue and the second layer of tissue. The main envelope is then inflated to gently separate the first layer of tissue from the second layer of tissue, thereby creating a working space between the two layers of tissue. An endoscope may be passed through the bore of the single elongated tube into the main chamber to observe the extent of separation of the layers of tissue. The main envelope is then returned to a collapsed state, detached from the elongated tube, and removed from the working space between the layers of tissue through the bore of the elongated tube. The toroidal inflatable chamber at the distal end of the elongated tube is then inflated into an expanded state. The anchor flange is slid distally along the elongated tube to compress the second layer of tissue between it and the expanded toroidal inflatable chamber to form a gas-tight seal. Insufflating gas is passed through the elongated tube into the working space to maintain the separation of the first and second tissue layers. An endoscope may be passed through the bore of the single elongated tube into the working space to observe within the working space.
Such a method (described in U.S. Ser. No. 07/911,714) of using either the apparatus of FIGS. 4A-4C or that of FIGS. 5A-5D to separate a first layer of tissue from a second layer of tissue will next be described with reference to FIGS. 6A-6H. For specificity, FIGS. 6A-6H will be described with reference to separation of the peritoneum from the properitoneal fascia in the course of repairing a hernia using the apparatus of FIGS. 4A-4C.
FIGS. 6A-6H show a longitudinal cross section of the lower abdomen. Incision I about 12-15 mm. long is made in the abdominal wall, and carried through the abdominal wall as far as, and including the properitoneal fat layer as shown in FIG. 6A. Distal end 115 of tube assembly 160 of apparatus 121 is then inserted into the incision to bring the distal end into contact with the peritoneum. Additional gentle pressure detaches the part of the peritoneum in the immediate vicinity of the incision from the overlying layer, as shown in FIG. 6B. FIG. 6B shows the peritoneum detached from the properitoneal fat layer. The main envelope cannot be seen in FIGS. 6A and 6B because it is inverted within the bore of the tube assembly.
A source of inflation fluid (not shown) is connected to valve 131. A gas, preferably air, is the preferred inflation fluid, but other gases, such a carbon dioxide can be used. A liquid, such as saline solution can be used, but liquids are less preferable because they change the optical properties of any endoscope inserted into main inflatable chamber 113. The flow of inflation fluid is turned on, which ejects main envelope 112 from the bore of tube assembly 160.
The inflation fluid progressively expands main envelope 112, and hence main inflatable chamber 113 defmed by the main envelope, into an expanded state as shown in FIG. 6C. The main envelope expands between the peritoneum and the properitoneal fat layer, and gently and progressively detaches an increasing area of the peritoneun from the overlying layer as it expands. When the main envelope is in its expanded state, the main inflatable chamber is preferably about 4"-6" (100-150 mm) in diameter.
Early in the process of expanding main envelope 112, an endoscope E is inserted into flapper valve 132 in port 125 as shown in FIG. 6C. Endoscope E is passed through the bore of tube assembly 160 into main inflatable chamber 113. Once the main envelope is partially expanded, the main envelope is sufficiently transparent for the extent of the detachment of the peritoneum to be observed using the endoscope.
When a sufficient area of the peritoneum is detached, the supply of inflation fluid is turned off. The inflation fluid is then vented from main inflatable chamber 113, and the main envelope progressively returns to its collapsed state. The peritoneum remains detached from the overlying layer, however, as shown in FIG. 6D. The main envelope is then removed from the bore of tube assembly 160. The different methods of removing the main envelope from the bore of the tube assembly for the different forms of the one-component apparatus (that of FIGS. 4A-4C and that of FIGS. 5A-5D) are described above.
After main envelope 112 has been removed from the bore of the tube assembly, the tube assembly is advanced into the incision in the direction of arrow 162 until the proximal end of envelope 145 of the toroidal inflatable chamber is in the properitoneal space, clear of the incision, as shown in FIG. 6E.
A suitable source (not shown) of an inflation fluid is attached to valve 153. A gas, such as air or carbon dioxide, can be used for the inflation fluid; alternatively, a liquid, such as saline can be used. Since the volume of inflation fluid required to inflate the toroidal inflatable chamber is small, about 15 ml in the preferred embodiment, the inflation fluid can be contained in a large syringe. Inflation fluid is fed into toroidal inflatable chamber 43 to expand the toroidal inflatable chamber to its expanded condition, as shown in FIG. 6F.
Anchor flange 155 is then advanced in the direction of arrow 159 along tube assembly 160 to bring the anchor flange into contact with the skin S of abdominal wall AW. Tube assembly 160 is then gripped, and the anchor flange is further advanced slightly. This forces the expanded toroidal inflatable chamber 143 into contact with the overlying layer, and slightly compresses abdominal wall AW, including the overlying layer but excluding the peritoneum P, between the expanded toroidal inflatable chamber and the anchor flange, as shown in FIG. 6G. Once adjusted, the anchor flange is locked in position on the tube assembly. The expanded toroidal inflatable chamber is held against the overlying layer and forms a gas-tight seal with the abdominal wall, excluding the peritoneum.
A suitable source (not shown) of insufflation gas is attached to first valve 131, and insufflation gas is passed through the bore of inner tube 135 into working space WS between the peritoneum P and the overlying layer created by separating the peritoneum from the overlying layer. The pressure of the insufflation gas re-separates the peritoneum from the overlying layer, as shown in FIG. 6H, and provides a working space in which repair of the hernia can be carried out. The bore of tube assembly 160 can be used to pass instruments, such as endoscope E, into the working space to perform the repair procedure. When no instrument is inserted into the bore of the tube assembly, insufflation pressure is maintained by the flapper valve.
As part of a hernia repair procedure, additional gas-tight trocar sleeves (not shown) are inserted through the abdominal wall into the working space. The same procedure described above in connection with FIG. 3I is used to attach a mesh patch to the properitoneal fascia over the site of the hernia The process can be observed using an endoscope passed through the bore of tube assembly 160, or through one of the additional trocar sleeves.
After the treatment procedure is completed, valve 131 is operated to release the insufflation gas from the working space WS. Valve 153 is operated to release the inflation fluid from toroidal inflatable chamber 143, which releases compression of the abdominal wall AW, excluding the peritoneum. Toroidal inflatable chamber 143 returns to its collapsed state, with its envelope 145 flush with the outer surface tube assembly 160. The tube assembly is then withdrawn from the incision, and the incision is closed using sutures or clips. The pressure of the viscera against the peritoneum returns the peritoneum into contact with the overlying layer. Over time, the peritoneum reattaches to the overlying layer.
In a second embodiment of a one-component apparatus according to U.S. Ser. No. 07/911,714, the introducing device is an outer elongated tube, and the insufflating device comprises an inner elongated tube mounted in the bore of the outer tube. The proximal ends of the tubes are flexibly coupled together. One end of the main envelope is everted with respect to the other, and is attached to the distal end of the outer elongated tube. The other end of the main envelope is attached to the distal end of the inner elongated tube. The main inflatable chamber defined by the main envelope is thus substantially toroidal. The outer elongated tube has an anchor flange slidably mounted on it. The anchor flange and the main inflatable chamber together form a gas-tight seal with the second layer of tissue.
Such second embodiment of a one-component apparatus is shown in FIGS. 7A-7B and 8A-8B. In this embodiment, a substantially toroidal shape of the main chamber avoids the need to detach and remove the main envelope at the end of the separation process, and the toroidal main chamber provides both the separating function of the main chamber and the sealing function of the toroidal chamber of the embodiment of FIGS. 4A-4C.
The apparatus of FIGS. 7A and 7B comprises tube assembly 260, including outer tube 237 to which is attached a twin port assembly 225 comprising first port 226 and second port 228. The first port is provided with a first flapper valve 202, including flapper valve seat 204. The second port is provided with a second flapper valve 206, including flapper valve seat 208. Each flapper valve seat forms a gas-tight seal with an instrument passed through it.
Tube assembly 260 also includes inner tube 235. Inner tube 235 is shorter than outer tube 237. The proximal end 210 of the inner tube is flexibly attached to the proximal end 222 of outer tube 237 and to first port 226. The flexible attachment enables the distal end 214 of the inner tube to move in the direction shown by the arrow 216. The first port communicates with the bore of inner tube 235, and the second port communicates with the bore of outer tube 237.
Insufflation valve 285 communicates with first port 226, and the bore of inner tube 235. Main chamber inflation valve 231 communicates with second port 228, and the bore of outer tube 237.
Main envelope 212 defines the main inflatable chamber 213 and comprises a cylindrical piece of an elastomeric material such a latex, silicone rubber, or polyurethane. The apparatus is shown with its main envelope in its collapsed state in FIG. 7B, in which the structure of the main envelope can also be seen. The main envelope preferably has a diameter smaller than the outside diameter of the inner tube. One end 230 of the main envelope is attached to distal end 214 of inner tube 235 by means of a suitable adhesive, such as an epoxy or cyanoacrylate adhesive. The other end 232 of the main envelope is everted (i.e., turned back on itself to bring the inside surface 234 of the main envelope to the outside) and attached to the distal end 236 of the outer tube using the same type of adhesive. The main envelope is preferably attached to the outer surfaces of the inner tube and the outer tube.
FIG. 7A shows main envelope 212 in its expanded state. To reach this state, a source of inflation gas is connected to valve 231 and the gas flows into the main inflatable chamber through the bore of outer tube 237. The pressure acting on surface 238 of the main envelope 212 causes the main envelope to assume the toroidal shape shown in FIG. 7A to define toroidal main chamber 213, with surface 234 defining the "hole" or "bore" through the toroidal main envelope. FIGS. 7A and 7B show the correspondence between the surfaces 234 and 238 of the main envelope when the main envelope is in a collapsed state (FIG. 7B) and in an expanded state (FIG. 7A).
Anchor flange 255 is slidably mounted on tube assembly 260, and can be locked in a desired position along the length of the tube assembly. Anchor flange 255 is identical or similar to anchor flange 55 (of FIG. 2A) and thus will not be described further.
FIG. 8A shows an endoscope E passed through second flapper valve 206, second port 228, and the bore of outer tube 237 into main inflatable chamber 213. The flexible mounting of inner tube 235 in the outer tube enables the endoscope to displace inner tube 235 in direction of the arrow 216 to gain access to the main inflatable chamber. The endoscope is inserted through the second port into the main inflatable chamber during tissue separation using the apparatus to observe the extent of the separation.
FIG. 8B shows an endoscope E passed through first flapper valve 202, first port 226, the bore of inner tube 235, and bore 234 of main envelope 212. The distal part of the endoscope emerges from the bore of the main 212, and can be advanced beyond the main inflatable chamber 213 to observe tissue such as the site of the hernia more closely. The endoscope is inserted through the first port, the inner tube, and the bore of the main envelope during insufflation using the apparatus. Instruments other than endoscopes can also be passed to the site of-the hernia through the first flapper valve, the first port, the inner tube, and the bore of the main envelope if desired.
As shown in FIG. 8B, main envelope 212 is in a partially collapsed state that it preferably assumes during the insufflation phase of the procedure. During this part of the procedure, the partially collapsed main inflatable chamber and anchor flange 255 together provide a gas-tight seal to prevent the leakage of insufflation gas. Alternatively, insufflation can be carried out with the main inflatable chamber in a fully expanded state.
In a method described in U.S. Ser. No. 07/911,714 of using the embodiment of FIGS. 7A, 7B, 8A, and 8B to separate a first layer of tissue from a second layer of tissue, the outer elongated tube pushes the main envelope in a collapsed state through an incision through the second layer of tissue to place the main envelope between the first layer of tissue and the second layer of tissue. The main envelope is then inflated to gently separate the first layer of tissue from the second layer of tissue, and to create working a space between the layers of tissue. An endoscope may be passed through the outer elongated tube into the main chamber to observe the extent of separation of the layers of tissue. The anchor flange is slid distally along the introducing device tube to compress the second layer of tissue between it and the main inflatable chamber, to form a gas-tight seal. Insufflating gas is then passed through the bore of the inner elongated tube and the bore of the main envelope into the working space to maintain the separation of the first layer of tissue from the second. An endoscope may be passed through the bore of the inner elongated tube and the bore of the main envelope into the working space to observe within the working space.
More specifically, in performing this method, an incision about 12-15 mm long is made in the abdominal wall, and carried through the abdominal wall as far as, and including, the properitoneal fat layer. The distal end of tube assembly 260 is then inserted into the incision into contact with the peritoneum. Additional gentle pressure detaches the part of the peritoneum in the immediate vicinity of the incision from the overlying layer (at this time, main envelope 212 is inverted within the bore of the tube assembly). A source of inflation fluid is then connected to valve 231. A gas, preferably air, is the preferred inflation fluid, but other gases, such a carbon dioxide can be used. A liquid such as saline solution can be used, but a gas is preferred to a liquid because liquids change the optical properties of any endoscope inserted into the inflatable chamber. The flow of inflation fluid is turned on, which ejects the main envelope 212 from the bore of tube assembly 260.
The inflation fluid progressively expands main envelope 212, and hence main inflatable chamber 213 defined by the main envelope, into an expanded state. The main envelope expands between the peritoneum and the properitoneal fat layer, and gently and progressively separates an increasing area of the peritoneum from the overlying layer as it expands. When the main envelope is in its expanded state, the main inflatable chamber is preferably about 4"-6" (100-150 mm) in diameter.
Early in the process of expanding main envelope 212, an endoscope is inserted into first flapper valve 202. The endoscope is passed through the bore of outer tube 237 into main inflatable chamber 213. Once partially expanded, main envelope 212 is sufficiently transparent for the extent of the separation of the peritoneum to be observed using the endoscope.
When a sufficient area of the peritoneum is separated, the supply of inflation fluid is turned off and the endoscope is removed from main inflatable chamber 213. Valve 231 is then opened to allow inflation fluid to vent partially from main inflatable chamber 213 (allowing main envelope 212 to return at least partially to its collapsed state). Alternatively, main envelope 212 may be kept fully expanded.
Anchor flange 255 is then advanced along tube assembly 260 to bring the anchor flange into contact with the skin of the abdominal wall. Tube assembly 260 is then gripped, and the anchor flange is further advanced slightly. This forces the main envelope 212 into contact with the overlying layer, and slightly compresses the abdominal wall, including the overlying layer but excluding the peritoneum, between the main envelope and the anchor flange. Once adjusted, anchor flange 255 is locked in position on the tube assembly, and main envelope 212 forms a gas-tight seal with the abdominal wall and the peritoneum.
A suitable source of insufflation gas is attached to second valve 285, and insufflation gas is passed through the bore of inner tube 235, and bore 234 of main envelope 212, into the working space between the peritoneum and the overlying layer. The pressure of the insufflation gas re-separates the peritoneum from the overlying layer, and provides a larger working space in which repair of the hernia can be carried out.
An instrument such as an endoscope can be passed through second flapper valve 206, the bore of inner tube 235, and bore 234 of main envelope 212, into the working space to perform a repair procedure. When no instrument is so inserted, insufflation pressure is maintained by second flapper valve 206.
After the treatment procedure is completed, valve 285 is operated to release the insufflation gas from the working space. Valve 231 is operated to release the inflation fluid from main inflatable chamber 213, which releases compression from the abdominal wall, excluding the peritoneum. Main envelope 212 returns to its collapsed state inside the bore of outer tube 237.
The tube assembly is then withdrawn from the incision, and the incision is closed using sutures or clips. The pressure of the viscera against the peritoneum returns the peritoneum into contact with the overlying layer. Over time, the peritoneum reattaches to the overlying layer.
In another method described in U.S. Ser. No. 07/911,714, access is provided through the abdominal wall from near the umbilicus to repair a hernia This method will be described with reference to FIGS. 9A-9I. This method is often preferable to the hernia repair methods described above in which the incision is placed close to the site of the hernia, since in practice, it is preferred to make the incision at or near the umbilicus because the boundary between the peritoneum and the properitoneal fat layer can be more directly accessed near the umbilicus. The midline location of the umbilicus is devoid of muscle layers that would otherwise need to be traversed to reach the properitoneal fat layer.
In the method of FIGS. 9A-9I, the main envelope is partially expanded, collapsed, and advanced toward the site of the hernia This sequence is repeated to progressively separate the peritoneum from the overlying layer and form the tunnel from the umbilicus to the site of the hernia. Then, at or near the site of the hernia, the main envelope is fully expanded to provide the working space at the site of the hernia The working space is then insufflated to maintain the separation of the peritoneum from the overlying layer. The method of FIGS. 9A-9I can be practiced using any of the two-component or one-component apparatuses described above. For specificity, the method will be described with reference to a two-component apparatus.
An incision about 12-15 mm long is made in the abdominal wall AW, and is carried through the abdominal wall as far as, and including, the properitoneal fat layer FL. The incision is made at the umbilicus U, as shown in FIG. 9A.
Distal end 15 of introducer tube 3 of separation component 1 is then inserted into the incision to bring the distal end into contact with the peritoneum P. Additional gentle pressure detaches the part of the peritoneum in the immediate vicinity of the incision from the overlying layer, as shown in FIG. 9B. In FIG. 9B, the peritoneum is shown detached from the properitoneal fat layer FL. Main envelope 12 cannot be seen in FIGS. 9A and 9B because it is inverted within the bore of introducer tube 3.
A source of a suitable inflation fluid (not shown), as previously described, is connected to valve 11. The flow of inflation fluid is turned on, which ejects main envelope 12 of main inflatable chamber 13 from the bore of introducer tube 3. The inflation fluid progressively expands main envelope 12, and hence main inflatable chamber 13 defined by the main envelope, into a partially-expanded state, as shown in FIG. 9C. The main envelope expands between the peritoneum and the properitoneal fat layer FL, and gently and progressively detaches an increasing area of the peritoneum P from the overlying layer near the umbilicus as it expands.
An endoscope (not shown) can be inserted into main inflatable chamber 13 through flapper valve 2 and the bore of introducer tube 3. The endoscope can be used to observe the extent of the separation of the peritoneum, as described above.
When main envelope 12 expanded such that the main inflatable chamber 13 is about one-fourth of its fully-expanded diameter, i.e., about 1.0"-1.5" (25-37 mm) in diameter, the supply of inflation fluid is turned off. Valve 11 is then operated to vent inflation fluid from the main inflatable chamber 13. The main envelope progressively returns to its collapsed state, as shown in FIG. 9D. The peritoneum portion DP that was separated by the main inflatable chamber remains detached from the overlying layer, as shown. Alternatively, the main envelope can be inflated to a fully-expanded state.
Separation component 1, including the collapsed main envelope 12, is then manipulated in the direction indicated by arrow 14, and then in the direction indicated by arrow 16, to advance distal part 15 of introducer tube 3 to the limit of the detached part DP of the peritoneum in the direction of the groin, as shown in FIG. 9E. An endoscope E inserted through flapper valve 2 into the bore of introducer tube 3 enables the position of the distal part 15 relative to the detached part DP of the peritoneum to be observed.
Once distal part 15 of the introducer tube has been positioned, the separation component 1 is clamped in position, or is gripped, and inflation fluid is once more passed through the valve 11 and the bore of introducer tube 3 into main inflatable chamber 13. The main envelope 12 expands once more, increasing the extent of the detached part of the peritoneum towards the groin, as shown in FIG. 9F. The increased extent of the detached part of the peritoneum is indicated by line DP' in FIG. 9F. The extent of the detached part of the peritoneum is increased in the direction from the umbilicus to the groin, but not in the direction transverse to this direction. Endoscope E is used to observe the extent of the separation.
The process of collapsing the main envelope 12, advancing the distal part 15 of the introducer tube to the limit of the detached part DP' of the peritoneum in the direction of the groin, holding the introducer tube in position, and partially re-inflating main envelope 12, is repeated until the detached part of the peritoneum includes the peritoneum over the site of the hernia This process provides a tunnel T between the incision at the umbilicus and the site of the hernia (as shown in FIGS. 9G, 9H, and 9I).
When the main envelope is in the vicinity of the site of the hernia H, main envelope 12 is filly inflated to form a working space WS including the site of the hernia This is shown in FIG. 9G.
The working space at the site of the hernia is then insufflated. With the two-component apparatus, inflation fluid is vented from the main inflatable chamber 13 to collapse main envelope 12, and the separation component 1 is withdrawn from tunnel T through incision I. Insufflation component 21 is introduced into the incision, and advanced through the tunnel until envelope 45 of toroidal inflatable chamber 43 lies within the working space WS, clear of the tunnel. Toroidal inflatable chamber 43 is inflated, the anchor flange is clamped in position, and insufflation gas is passed into the working space, as shown in FIG. 9H. Toroidal inflatable chamber 43 provides a gas-tight seal with the entrance of the tunnel.
FIG. 9I is a plan view of the abdomen with insufflation component 21 in place. The anchor flange has been omitted for clarity. Toroidal inflatable chamber 43 provides a gas-tight seal with the entrance of tunnel T. The extent of the separated peritoneum is indicated by dotted line DP. It can be seen that the lateral extent of the separated peritoneum is considerably greater in working space WS than in tunnel T.
At this stage, if a one-component apparatus had been used (with the main inflatable chamber remaining in the working space), inflation fluid would be vented from the main inflatable chamber to collapse the main envelope, and the main envelope would be withdrawn from the working space through the bore of the tube assembly. The tube assembly would be partially withdrawn until the envelope of a toroidal inflatable chamber 43 lies within the working space, clear of the entrance to the tunnel. The toroidal inflatable chamber 43 would then be inflated, the anchor flange clamped in position, and insufflation gas passed into the working space, as already described. The toroidal inflatable chamber 43 would seal against the entrance from the tunnel into the working space.
Alternatively, if another type of one-component apparatus had been used (with the main inflatable chamber remaining in the working space), the main envelope would preferably be returned to a partially collapsed state, and the tube assembly partially withdrawn until the main inflatable chamber lies within the working space, adjacent to the entrance of the tunnel. The anchor flange would be clamped in position, and insufflation gas is passed into the working space as already described. The partially-collapsed main chamber would seal against the entrance from the tunnel into the working space.
Regardless of the embodiment of the apparatus used to create the insufflated working space WS shown in FIG. 9I, the hernia is then repaired using a procedure such as that described in connection with FIG. 3I.
Before either component 1 or component 21 (or a one-component apparatus that performs the functions of both components 1 and 21) is inserted into the patient, its inflatable envelopes and chambers are deflated and packed into a sheath. One method of packing an inflatable chamber in its deflated, compact state is to roll the chamber inwardly from opposing lateral sides.
Above-referenced U.S. Ser. No. 08/405,284 discloses a device which performs both dissection and retraction of tissue layers while at least a part of the device remains in the patient throughout the dissection and retraction procedure, so that the user need not remove one assembly from the patient and then insert a second assembly into the patient (searching for the dissected spatial plane in order to deploy the second assembly in the proper position) between the dissection and retraction steps. In a preferred implementation, the distal end of the device is moved to a position between tissue layers in the patient. A first balloon is then inflated between the tissue layers to dissect the tissue layers. A second balloon, which is used to retract the tissue layers, is then inflated between the tissue layers. The distal end of the device for introducing and inflating first balloon remains in the patient until the second balloon has been inflated, so that the tissue layers remain at least partially separated at all times after initial introduction of the device between such layers. After retracting the tissue layers with the second balloon, the first balloon is deflated, e.g., by a puncturing step which creates an opening in the first balloon. Instruments are then introduced into a working space through the opening in the first balloon. The second balloon, which can be positioned in the interior of the first balloon, is inflated to seal the working space so that insufflating fluid is impeded from escaping.
Until the present invention, it had not been known how to view a space between tissue layers while (or after) dissecting the layers with a balloon, without removing any portion of the dissecting apparatus including the balloon, but also without image degradation resulting from viewing through balloon wall. Nor, until the present invention, had it been known to design a balloon (suitable for tissue dissection, tissue retraction, and/or instrument anchoring) to have any of a wide range of inflated shape and pressure characteristics. For example, it had not been known to design a tissue dissection balloon to have inflated shape and pressure characteristics tailored for producing a working space (between dissected tissue layers) having a particular size and shape selected from a broad range of sizes and shapes.